Jet assembly



Jan. 22, 1957 E. UMBRICHT JET ASSEMBLY Filed Feb. 2 1953 IN VEN TOR.EM/Z. (1MB R/C If 7' United States Patent 2,778,685 JET ASSEMBLY EmilUmbricht, Jackson, Mich., assignor to Ajem Laboratories, Inc., Detroit,Mich.

Application February 2, 1953, Serial No. 334,420

12 Claims. (Cl. 299-121) This invention relates to jet assemblies foruse in power Washers such as are used for cleaning metal. In such powerwashers, a jet of cleaning solution, for example Water with chemicaldetergents, is forced at relatively high velocity over the surface offinished or semi-finished parts to clean the surfaces and prepare themfor painting, assembly, or other treatment.

It is important that the cleaning solution strike the surface to becleaned with suflicient velocity to remove the undesired surface filmand also that the spray of liquid to be spread over a substantialcrosssectional area so that the entire surface will be cleanedefficiently. In practice, these two conditions are diflicult to meet. Ifthe cleaning solution is spread over a larger area by breaking a singlejet into many small jets or causing it to form a spray, the velocity andforce of the liquid may be reduced to such an extent that the cleaningaction is ineffective. Moreover, the velocity and force of the liquidstriking the surface may vary to a substantial extent over thecross-sectionxof the spray, further reducing the effectiveness andefficiency of the cleaning operation. Prior arrangements which make useof a relatively large number of small orifices for ejecting the cleaningsolution are undesirable because the orifices are easily clogged bysolid material contained in the cleaning solution.

The present invention provides methods and apparatus for producing adiverging conical spray of cleaning solution which is propelled at highvelocity and which has a large working zone in which the velocity andforce of the liquid is substantially uniform over the cross-section.

Ina preferred embodiment of the invention, a generally bullet-shapeddirector is supported in front of a relatively large opening with thenose of the director extending toward the center of the opening. Thecleaningliquid is forced through the opening so that it strikes thedirector and is spread outwardly into a cone shape. Because of theshaped spray and position of the director, part of the liquid closesbeyond the director to form a uniform distribution of the moving liquidspray. This arrangement produces a cleaning spray distributed uniformlyover a relatively large cross-sectional area throughout which the liquidis propelled at high and substantially uniform velocity.

The director incorporated in the various embodiments of this inventionis not to be confused with the many types of deflectors which have beenpositioned in front of orifices to change the direction of the stream orto break it up into a spray as for distributing water over a large area.Such spatter plates produce substantial amounts of very fine spray ormist and always cause a marked reduction in the linear velocity of theliquid.

The distinguishing characteristics of this invention together with otheraspects and advantages of it will be in part pointed out in and in partapparent from the following description considered in conjunction withthe accompanying drawings, in which:

Figure 1 is a diagrammatic representation of a et as- Patented Jan. 22,1957 sembly embodying the invention in use to spray cleaning liquid overthe surfaces of a gear wheel;

Figure 2 is a side elevational view of the jet assembly of Figure 1showing the supporting arrangement for the director;

Figure 3 shows another embodiment of the invention having a differentshaped director; and

Figure 4 is a perspective view of another embodiment in which thedirector is mounted at an angle to the axis of the pipe through whichliquid flows to the jet assembly.

Figure 1 indicates the operation and manner of using a jet assemblyembodying the invention. Cleaning solution, made up for example of waterand a detergent, is-

supplied under pressure through a pipe 2 and is ejected through arelatively large orifice 4 formed in the end of thepipe 2. A generallybullet-shaped director element 6 is positioned directly in front of theopening 4 and causes the water to be deflected outwardly as indicated bythe broken lines 8 forming a cone-shapedspray, Beyond the end of thedirector 6, part of the water is deflected inwardly, as along the brokenlines 10, to fill the center of the cone so that for a substantialdistance, for example between the broken lines 1 2 and 14, the water isinterfere materially with the flow of liquid or the formattion of thespreading cone of liquid spray. 'In the .embodiment of Figures 1 and 2,the director 6 is supported by a generally U-shaped bracket 18 formed-ofmetal strip. The ends of the bracket 1-8 are welded or otherwise securedto and supported by the pipe 2 andthe'remaining portion ofthe bracketforms a closed loop to which the director 6 is secured, for example bywelding the bracket 18 in a transverse groove, as at 20, across theblunt end of the director. The metal strip ispositioned edgewise withrespect to the direction of the liquid stream so as-to cause minimuminterference with the flow. If desired, the edges of the bracket uponwhich the liquid impinges can be rounded or knife-edged to furtherreduce the effect of the bracket. It would h e-apparent that the mannerof supporting the director is not critical to the invention so long asthe supporting members do not cause excessive interference with theliquid stream.- Thus, f-or'example, one-half of the U-shaped bracket-18may be omitted provided the bracket is formed of material sufiicientlystrong that the single arm will provide adequate mechanical support forthe director. It is, of course, convenient for the director to besupported rigidly from the pipe through which the liquid is delivered tothe orifice, but if desired it may be supported from an entirelyseparate structure so long as it is positioned properly with respect tothe orifice 4.

The shape of the director is critical only to the extent that the angleof incidence of the various parts of the stream of liquid from theorifice 4 on the surface of the director 6 should be less than thecritical angle at which the liquid would be broken into a spray or mistof fine droplets with marked reduction in the velocity of the liquid.

Thus the tip 22 of the director 6 preferably is pointed,

as shown in Figure 2, or rounded with a small radius of inch, anover-all length, indicated at A in Figure 2, of 1.5 inches, and waspositioned symmetrically with respect to' the liquid stream and theorifice 4. As shown in Figure 2, the director is so proportioned thatwhen the distance A is 1".5' inches and the maximum diameter is one inchasin the practieal'embodiment mentioned above, the. includedangle'between lines in a common plane extending between the tip of thedirector and oppositely disposed. surface points at its maximum diameteris not significantly greater than thinty-seven degrees. of the directorwas positioned 0.44 inch from the face of the orifice 4, as indicated bythe dimension B. The convex surfaces of the director 6 had a constantradius of curvature of approximately two inches, arranged so that twolines on opposite sides of the director and tangent'to its surfaceimmediately adjacent the tip 22 form an angle, indicated at C, ofapproximately 80 degrees. All surfaces were smooth and polished'so as toproduce minimum turbulence in the flow of the liquid.

In general, the dimensions and shape of directors of the characterdescribed above will depend upon the size of the orifice 4, the positionof the director, the velocity and characteristics of the cleaningliquid, and the area over which his desired to spread the liquid.

For best results in most applications the director 6 should have amaximum mean diameter equal to 1 /2 to 2 /2 times the mean diameter ofthe orifice 4, and its length should be between 2 /2 and 3 /2 times theorifice diameter. The distance B from the tip 22 of the director 6 tothe face of the orifice 4 should be at least equal to the diameter ofthe orifice and may be as much as several times this distance.

Ifdesired, the tip of the director can be rounded, as indicated in theembodiment of Figure 3 provided the radius; of curvature of the surfaceof this nose portion is not greater than one-halfthe diameter of theorifice opening'. The remaining convex surface of the director can be ofconstant radius of curvature or the radius of curvature mayv-ary alongthe length of the director, but in accordance with the foregoinglimitations abrupt changes in the direction of the surface should beavoided and significant portions of the surface should not be at suchabrupt angles to the direction of the impinging stream as would causespattering or lateral dispersion of the stream. The surface'of thedirector at its maximum diameter is tangent to a cylindrical surfacewhose axis is substantially parallel to the direction of flow oftheliquid as it approaches the director. The director may have a relativelyblunt end nearthis maximum diameter as shown in Figure 1 or the end ofthe director opposite the approaching streammay be tapered, conical, orbullet-shaped but should have an equally or more sharply convergingconfiguration than the nose end of the director as shown in Figure 3.The director of Figure 3, can, if desired, be formed with an abrupt orblunt end at any point, as along any of the broken lines 24, 26, and 2.8of Figure 3.

The director may have a portion of uniform diameter in the region ofmaximum diameter, for example as indicated at 30 in Figure 3. The lengthof this cylindrical surface portion 24' in the direction of thelongitudinal axis of the director may be between Zero (as in theembodiment of Figure l) and a distance equal to the diameter of theorifice opening.

Figure 4 shows another embodiment of the invention in which the axis ofthe pipe 2B is at an angle to the longitudinal axis of the director 63;this angle may be as much asforty-five degrees if desired. The director6B, however, remains with its longitudinal axis parallel to the axis ofthe orifice 4B and parallel to direction of flow of liquidfrom theorifice 4B.

It will be clear also that any desired passageway may be employed toconduct the cleaning liquid to the jet assembly and to form it into asolid stream flowing toward the nose of the director. For example, oneor more holes. may be drilled in the side of a pipe carrying the Thepointed tip 22 cleaning liquid with a director positioned in front ofeach opening'as described above. Eachof the directors may be supportedfrom the pipe by a strap type clamp formed of two members each having anarcuate clamping surface and arranged to engage opposite sides of thepipe. One of these members may be provided with a hole, in alignmentwith an opening in the pipe, which serves as the orifice. The twomembers may be clamped tightly around the pipe by bolts or otherfastening devices, suitable sealing material being provided to preventthe cleaningliquid from leaking into any space between the pipe and theclamp member. The director may be supported frornthe pipe or from one ofthe clamp members, or by other means, it being apparent that the mannerof support is not critical except asindicated by the limitations setforth herein.

It will be apparent that the particular descriptions set forth above arefor the purposes of illustrating the principles of the invention so thatothers may adapt it to their particular circumstances of use. It will beapparent that certain details of the construction have been set forthonly for the purpose of illustrating a working embodiment of theinvention and not for the purpose of limitation, except as isapparentherefrom or from the following claims.

What is claimed is:

1. In a'power washer for spraying cleaning liquid with high hydraulicforce over surfaces to be cleaned, a jet assembly comprising a bodyhaving a passageway for conducting cleaning liquid and an orifice forejecting the liquid in a substantially solid stream, a generallybulletshaped director, said director having a rounded tip portion withradius of curvature not significantly greater than a distance equal toone-half the mean diameter of said orifice, said director having a backportion of a diameter between 1.5 and 2.5 times the mean diameter ofsaid orifice and means supporting said director in front of and spacedfrom said orifice with its tip in alignment with and facingtoward saidorifice.

2. In apower washer for spraying cleaning liquid with high hydraulic.force over surfaces to be cleaned, a jet assembly comprising a bodyhaving a passageway for conducting cleaning liquid and an orifice forejecting the liquid in a substantially solid stream, a generallybullet-shaped director, and means supporting said director in a fixedposition in front of and spaced from said orifice with its tip inalignment with and facing toward said orifice, said director having arounded tip portion with radius of curvature not significantly greaterthan a distance equal to one-half the mean diameter of said orifice, theentire remaining surface of said director in the path of the liquid fromsaid orifice having radius of curvature at least equal to twice the meandiameter of said orifice, and the maximum mean diameter of said directorbeing between 1.5 and 2.5 times the mean diameter of said orifice.

3. In a power washer for spraying cleaning liquid with high hydraulicforce over surfaces to be cleaned, a jet assembly comprising. a bodyhaving a passageway for conducting cleaning liquid and an orifice forejecting the liquid in a substantially solid stream, a generallybulletshaped director, and means supporting said director in a fixedposition in front of andrspaced from said orifice with its tip inalignment with and facing toward said orifice, said director being soproportioned that the included anglebetween lines in a common planeextending between the tip of said director and oppositely disposedsurface points at its maximum diameter is not significantly greater thanthirty-seven degrees.

4. In a. power washer for distributing liquid spray, a jet assemblycomprising a body having a passageway for conducting cleaning liquid andan orifice for ejecting the liquid in, a substantially solid stream, agenerally bulletshaped director, and 'meanssupporting said director in afixed position in front of and spaced from said orifice with its tip inalignment with and facing toward said orifice, the surface of saiddirector at its maximum diameter being tangent to a directionsubstantially parallel to the direction of flow of said liquid as itleaves said orifice, the diameter of said director at its maximum diameter being between 1.5 and 2.5 times the mean diameter of saidorifice.

5. In a power washer for spraying cleaning liquid with high hydraulicforce over surfaces to be cleaned, a jet assembly comprising a bodyhaving a passageway for conducting cleaning liquid and an orifice forejecting the liquid in a substantially solid stream, a generallybulletshaped director each transverse cross-section of which is circularin outline, said director having a rounded tip portion with a radius ofcurvature not significantly greater than a distance equal to one-halfthe mean diameter of said orifice, and means rigidly supporting saiddirector in a fixed position in front of and spaced from said orificewith its tip in alignment with and facing toward said orifice, thelength of said director being between 2.5 and 3.5 times the meandiameter of said orifice.

6. In a power washer for distributing liquid spray uniformly over asubstantial area, a jet assembly comprising a body having a passagewayfor conducting cleaning liquid and an orifice for ejecting the liquid ina substantially solid stream, a generally bullet-shaped director, andmeans supporting said director in a fixed position in front of andspaced from said orifice with its tip facing toward said orifice, saiddirector having a smooth surface with a tip portion in alignment withand pointed toward said orifice, said smooth surface having a radius ofcurvature at least equal to twice the mean diameter of said orifice anddiverging at said tip portion at an angle lying between 60 and 90 sothat a substantial Bernoulli effect is exerted on the liquid of saidstream impinging on the surface of the director, a substantial portionof the liquid.

flowing along the surface of the director and being deflected inwardlyafter it leaves the director to form an expanding conical spray withsubstantially uniform distribution over its cross-section. v

7. In a power washer for distributing liquid spray uniformly over asubstantial area, a jet assembly comprising a body having a passagewayfor conducting cleaning liquid and an orifice for ejecting the liquid ina substantially solid stream, a generally bullet-shaped director, andmeans supporting said director in front of and spaced from said orificewith its tip in alignment with and facing toward said orifice, themaximum diameter of said director being between 1.5 and 2.5 times themean diameter of said orifice.

8. In a power washer for distributing liquid spray uniformly over asubstantial area, a jet assembly comprising a body having a passagewayfor conducting cleaning liquid and an orifice for ejecting the liquid ina substantially solid stream, a generally bullet-shaped director, andmeans supporting said director in a fixed position in front of andspaced from said orifice with its tip in alignment with and facingtoward said orifice, the over-all length of said director being between2.5 and 3.5 times the mean diameter of said orifice. 1

9. In a power washer for distributing liquid spray uniformly over asubstantial area, a jet assembly comprising a body having a passagewayfor conducting cleaning liquid and an orifice for ejecting the liquid ina sub stantially solid stream, a generally bullet-shaped director, andmeans supporting said director in afixed position in front of and spacedfrom said orifice with its tip facing toward said orifice, the distancebetween said orifice and said tip being at least equal to the meandiameter of said orifice, tangents to oppositesides of the surface ofsaid director near said tip defining enclosed angles between and 10. Ina power washer for spraying cleaning liquid with high hydraulic forceover surfaces to be cleaned, a jet assembly comprising a body having apassageway for conducting cleaning liquid and an orifice for ejectingthe liquid in a substantially solid stream, a generally bulletshapeddirector, and means supporting said director in a. fixed position infront of and spaced from said orifice with its tip facing toward saidorifice, said director being so shaped that every cross-section thereofin a plane perpendicular to the direction of flow of said liquid throughsaid orifice is circular in outline and so that conical surfacestangentto the surface of the director adjacent its tip will defineenclosed angles of between 6t) and 90 degrees.

11. in a power washer for spraying cleaning liquid with high hydraulicforce over surfaces to be cleaned, a jet assembly comprising a bodyhaving a passageway for conducting cleaning liquid and an orifice forejecting the liquid in a substantially solid stream, a generallybulletshaped director, and means supporting said director in a fixedposition in front of and spaced from said orifice with its tip facingtoward said orifice, the director having a ball. shaped nose with radiusof curvature not significantly greater than one-half the mean diameterof said orifice, the distance between the nose of the director and saidorifice being at least equal to the mean diameter of said orifice, thesurface of said director at its maximum diameter being tangent to adirection substantially parallel to the direction of flow of said liquidas it leaves said orifice.

12. in a power washer for distributing liquid spray, a jet assemblycomprising a body having a passageway for conducting cleaning liquid andan orifice for ejecting the liquid in a substantially solid stream, theaxis of said orifice being at an angle to said passageway less than 45,a generally bullet-shaped director, means supporting said director infront of said orifice with its tip facing toward said orifice and spacedtherefrom with its longi-' tudinal axis parallel to the axis of theorifice, the portion of the surface of the director in the path of thefluid from said orifice being convex, and said director being soproportioned that the included angle between lines in a common planeextending between the tip of said director and oppositely disposedsurface points at its maximum diameter is not significantly greater thanthirtyseven degrees.

References'Cited in the file of this patent UNITED STATES PATENTS

